Certain polycyclic aromatic hydrocarbons destroy oocytes in rodent ovaries. The mechanism of oocyte toxicity appears to depend upon ovarian metabolism of the polycyclic aromatic hydrocarbons to reactive intermediates which destroy oocytes. Experiments exploring the role of metabolic activation suggest that metabolism determines the rate of ovotoxicity but not the extent of oocyte destruction which occurs. The metabolic pathway to the proximate ovotoxin(s) is being explored using authentic metabolites of the polycyclic aromatic hydrocarbons. The role of ovarian and extra-ovarian metabolism in ovotoxicity is being explored. The role of detoxification in determination of the extent of oocyte destruction is being investigated. The effect of polycyclic aromatic hydrocarbons on reproductive performance of rodents is under investigation. The sensitivity of non-human primates to oocyte destruction by polycyclic aromatic hydrocarbons is being explored.